The generator matrix

 1  0  1  1  1
 0  1 2a^2+3  a 3a^2+2

generates a code of length 5 over GR(64,4) who´s minimum homogenous weight is 28.

Homogenous weight enumerator: w(x)=1x^0+280x^28+35x^32+1792x^35+1960x^36+28x^40

The gray image is a code over GF(8) with n=40, k=4 and d=28.
This code was found by Heurico 1.16 in 0.000181 seconds.